Anti-jamming device for typewriter type bars



April 7, 1959 H. L. LAMBERT ErAl. 3

- ANTI-JAMMING DEVICE FQREYPEWRITER TYPE BARS Filed Mai; e, 1957SShee'ts-Sheet 1 INVEN TORS HARRY L. LAMBERT ATTORNEYS a v I I Ba 5 k?April 7, 1959 v H. L. LAMBERT ETAL 2,880,837

ANTI-JAMMING DEVICE FOR TYPEWRITER TYPE BARS Filed May 6, 1957 :sSheets-Sheet 2 INVENTORS HA RRY L.LAMBERT. PAUL F. PAGE ATTORNEYS April7, .1959 H. L. LARFBERT ETAL 3 ANTI-JAMMING DEVICE FOR TYPEWRITER TYPEBARS v Filed May 6, 1957 I I y s Sheets-Sheet a INVENTOR5 HARRY L.LAMBERT PA L F. PAGE ATFONEYS H w-u VANTI-IAMMING DEVICEFOR mrwmm Y 7TYPE BARS Harry Long Lambert and Pauli F. Page, West Hartford,

'Conn.,'assignors to Royal McBee 'Corporationylort Chester, N.Y.,acorporation of New York Application May 6,1957,SerialNo.657,441

1 ai s-j 21- This, invention relates to an. anti jamming' device forprintingniaehines, 'and' more particularly relates to. a mechanism forautomaticaly disabling and enabling p the type bar actuatin'glinkag'esof'an electric typewriter..

Each typing action of'a'con'ventional electrictype writer is initiatedby operatively engaging a coupling" element of the typ'ebar actuatinglinkage with a'jpower rolll, Selective depressioniofthe various keys ofthe machine serves to' sequentially couple the respective couplingelements with said power roll'to thereby opera-' tively displace thecorrespondingtype bars through their respective printing strokes.Thistyping action may continue aslong as the power rollfis beingrotatably driven.

When the machine'is to beidle for a period of time the power supplyswitch is manually or automatically turned ofi and the power roll is nolonger driven. In this con-' dition of the machine one'or'moreof saidcoupling ele-' ments may be engaged with the stationary roll by theaccidental or deliberate depre'ssionofthe-typewriter keys. When thepower supply switch is subsequently turned on,

the variouscouplingelements which have been engaged with the powerroll'will be simultaneously actuated to, 1;; thereby drive thecorresponding type bars towards'the' printing line, .of .the-.machine...;Theresultant mutual interference between the type bars seemnttamucause said bars to jam up as theyapproach the typewriter platen. Such anoperation of the machine is obyiously undesirable" not" only because ofthe l time consuming necessity of manuallynestoring the type bars "totheir normal positions but also because such a jamming action may bendor otherwise damage the type bars involved.

One object of the instant invention is to provide a novel means foreliminating the untimely actuation and the jamming of the type bars of atypewriter when the power supply switch of the machine is turned on.

Another object of the invention is to provide a simple reliablemechanism for disabling the coupling elements of a typewriter during thetime when the machine is not in use.

A further object of the invention is to provide a mechanism which iscapable of disabling and enabling the coupling elements of an electrictypewriter and which is automatically operated in response to themanipulation of the power supply switch.

Still another object of the invention is to provide a mechanism which iscapable of disabling and enabling the type bar coupling elements of anelectric typewriter and which is locked in its enabling condition whenthe power supply switch is turned on, and is released to its disablingcondition when said switch is turned 01f.

Other objects will become apparent as the disclosure progresses.

In the drawings:

Figs. 1 and 2 are side elevational views of the antijamming mechanismand the related parts of a convent i o n al electric typewriter and showthe positional relation between said parts and the elements of saidmechq linkages may? cor'nprise'v anismlwhen ,theflpower supplyiswitch isin. the onfand.

Fig. 3 is a'front e'levational view'showingf the antijammingmechanismand jits'f structural relation to the adjacent-parts,offthejfmachine. 1=

v'l'here-are sleve'ralfd fi ent ypes of P writers. For example, thepowergroll "maycomprise a' longitudinally grooved cylinder. and theassociated coupling' elements forfthejvarious type bar. linkages maycomprise a seriesof'carrierpawls wliich are selectively en-L gaged withf the jgrooves 'df'lthl'e ipower driven cylinder On theotherhan t epoweri m v' c mp s cy dsr; having an outer coating of hjafrdrubber, orthelike, while i the associated coupling'f'elenjie'ntfs fer the varioustype;bar series ofjperipherally knurled pivoted. cams 'v'yhich'. are,selectively friction ally 'engaged with the outer,sur'r'acesiof saidcoatedgcylinder."

For thepurposes of illustration the instant'invention is shownwanddescrihed as embodied inf'an electric type-.1 writer of a type."hav'inga,groovedcylindrical power .roll

and a plurality [of associated jcarrier pawls. Itwill be apparenthowever.ithat the' invention is capable'ofi'being used withlequaleflicacyjin' electric"typewriters of a type having the above descri 'ed"coated power lroll'an'd. associated knurled cams.

For the sakeof'lclarity the eratiyelyor,structurally perfinent to. theinstant invention hav'been omitted from th edrawin'gst It'will beunderstood that the various elements shown are suitably'sup- Pom-ed? P-l312 rame 9f, ,,t,he machine in a ma well. lundveIstobdtifiothe aReferring to the drawings there. is shown a.conventional type,snatchfroll l1 which' jis rotatably driven in a' counterclockwisedirection as noted by arrow 2. vPivot-I ally mounted adjacent.the"snatchf roll 1 is a normal complement of spring'biased type barac'tuating carrier pawls 3 each having a snatchf roll engaging nose 4.Cooperating with .eachpawl 3jis a pivoted latch 5 which operativeengagement with the snatch roll 1 as shown by the dotted lines ofFig. 1. This key controlled selective coupling of the type bar actuatingpawls 3 and the roll 1 is of a conventional nature and need not befurther particularized here.

Fixedly mounted between the machine side frames 6 and 7 is an elongatedcomb member 8 to which is secured a pair of spaced upwardly extendingbrackets 10 and 11. Said brackets pivotally support a ball 12 by meansof pins 13 and 14. Springs 15 and 16 are connected between the fixedcross member 17 and the respective side arms 18 and 19 of bail 12 andbias the bail in a counterclockwise direction so that the body portion20 thereof engages the lower edges of said pawls 3. A forwardlyextending arm 25 formed on the left end of bail 12 is provided with aheaded stud 26 which is slidably engaged by the walls of an elongatedslot 27 formed in the lower end of a link 28. The upper end of link 28is pivotally connected by means of stud 30 to the rearward end of alever 32 which is rotatably mounted on the hub 34 of the manuallyoperated throw arm 35 of the typewriter power supply switch. A bent overear 38 formed on the upper edge of lever 32 overlies the rearwardlydisposed extension 40 of said throw arm 35. A laterally disposed bentover portion 42 is also provided at the rearward end of said lever 32.

On stud 43 of the left side frame 7 of the machine there is pivotallymounted a lever 44 which has a shoulder 1 lwer rolls and type;baicoupling elements usedin'conventional electrictypeg;

'various' parts and. components of the electric; typewriterfwhich arenot o'p- 45 and a forwardly extending cam following finger 46 formedthereon. A spring 48 biases lever 44 in a counterclockwise directioninto engagement with the bent over portion 42 of lever 32. The forwardend of finger 46 is adapted to be engaged by the cam surface 50 of thethrow arm 35 when the latter is moved clockwise to the off positionshown in Fig. 2.

When the typewriter is in normal use and the switch throw arm 35 is inthe on position shown in Fig. 1 the lever 32 will be locked in itscounterclockwise position by reason of the shoulder 45 underlying thelaterally disposed bent over portion 42 of said lever 32. Link 28 willthereby maintain the bail 12 in its clockwise position against theaction of springs 15 and 16 whereby the bail body portion 20 remainsspaced a sufiicient distance below the pawls 3 to allow said pawls tosubsequently drop into engagement with the snatch roll 1 in response tothe depression of the typewriter keys.

When the machine is to be idle for a period of time and the power supplyswitch throw arm 35 is manually or automatically moved to the o positionshown in Fig. 2 the cam surface 50 of said arm 35 engages and rearwardlydisplaces the finger 46 whereupon shoulder 45 of lever 44 is moved outfrom under the bent over portion 42 of lever 32. This will free the bail12 for counterclockwise rotation, under the action of springs 15 and 16,to a position wherein the bail body portion 20 engages the lower edgesof pawls 3 thereby blocking the latter from moving into operativeengagement with the snatch roll 1. Thereafter it will be impossible tooperatively couple any of the type bars to the snatch roll prior to theturning on of the power supply switch, hence the possibility of the typebars jamming as above described is eliminated.

When the switch throw arm 35 is restored to the on position of Fig. lthe rearward extension 40 of said arm 35 cooperating with the bent overear 38 will rotate lever 32 and lift link 28 thereby moving the bail 12to its clockwise or inoperative position, the bent over portion 42 oflever 32 having slid upwardly along the forward edge of lever 44 untilshoulder 45 of said lever 44 is moved into locking position beneath saidportion 42 under the action of spring 48.

It will be seen that the above described anti-jamming '4 the operativecondition of the typewriter power supply switch.

While there is in this application specifically described one form whichthe invention may assume in practice, it will be understood that thisform of the same is shown for purposes of illustration only and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appended claims.

The invention claimed is:

1. In a typewriter having a frame, a plurality of type bars movablymounted on said frame, drive means for said type bars, switching meansfor controlling said drive means, and means for selectively couplingsaid type bars to said drive means; the improvement comprising a bailpivotally supported on said frame and adapted to move into and out ofengagement with said coupling means, spring means for biasing said bailinto engagement with said coupling means, locking means for retainingthe bail out of engagement with said coupling means against the actionof said spring means, and means for releasing said locking means inresponse to the operation of said switching means.

2. In a typewriter having a frame, a plurality of type bars movablymounted on said frame, power drive means for said type bars, anelectrical switch for controlling said drive means, and means forselectively coupling said type bars to said drive means; the improvementcomprising a bail pivotally' mounted on said frame and adapted to bemoved into and out of engagement with said coupling means, spring meansnormally urging said bail into engagement with said coupling means,locking means for retaining said bail out of engagement with saidcoupling means, means responsive to the placing of said switch in theoff condition for releasing said locking means to thereby allow saidbail to move into engagement with said coupling means, and meansresponsive to the placing of said switch in the on condition for movingsaid bail out of engagement with said coupling means.

References Cited in the file of this patent UNITED STATES PATENTS

